Solve for $r$. $0.5(r+2.75) = 3$
Explanation: Let's divide and then subtract to get $r$ by itself. $\begin{aligned}0.5(r+2.75) &= 3 \\ \\\\ \dfrac{0.5(r+2.75)}{{0.5}} &= \dfrac{3}{{0.5}} ~~~~~~~\text{divide each side by } {0.5}\\ \\ \dfrac{\cancel{0.5}(r+2.75)}{\cancel{{0.5}}} &= \dfrac{3}{{0.5}} \\ \\ r+2.75&= \dfrac{3}{{0.5}} \end{aligned}$ $\begin{aligned} r+2.75&= 6 \\ \\ r+2.75 {-2.75}&=6{-2.75}~~~~{\text{subtract }2.75} \text{ to get } r \text{ by itself }\\ \\ r+\cancel{2.75} {{-}\cancel{{2.75}}}&= 6{-2.75}\\ \\ r &=6{-2.75}\end{aligned}$ The answer: $r={3.25}$ Let's check to make sure. $\begin{aligned} 0.5(r+2.75) &= 3 \\\\ 0.5({3.25}+2.75) &\stackrel{?}{=} 3 \\\\ 0.5(6)&\stackrel{?}{=} 3 \\\\ 3 &= 3 ~~~~~~~~~~\text{Yes!} \end{aligned}$